Coating process and apparatus
OwnerJoachim Sacherinventor
Life of this patent
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Abstract
In a process and apparatus for coating the front and/or rear facets of semiconductor laser diodes with antireflection layers of minimal reflectivity, the coating material is deposited on the facets while at least one laser parameter is monitored, in-situ, for determining the coating thickness of the individual antireflection layers resulting in the minimum reflectivity of the coating and the respective coating procedure is terminated when the laser parameter indicates that such coating thickness has been reached.
Claims6
A process for coating at least one of the front and rear facets of semiconductor laser diodes (lasers) with antireflection layers consisting of partial layers of minimal residual reflectivity, comprising the steps of:
- placing a plurality of semiconductor lasers in a receiver for concurrent coating of their facets,
- using one of said lasers in said receiver as a monitor laser, which is monitored to determine the coating state of all of the lasers in said receiver,
- depositing various coating materials on said facets to form said partial layers, in-situ monitoring at least one laser parameter for determining, on a real time basis, the optimum coating thickness of each of said partial layers for best anti-reflection properties, and terminating the coating procedure for each partial layer when said at least one laser parameter indicates that the optimum thickness of the respective partial layer has been reached, said at least one laser parameter comprising at least one of:
- a) the power of the light emitted from at least one of the front and the rear facets
- b) the quantum efficiency of the light emitted from at least one of the front and rear facets of the laser,
- c) the wavelength of the light emitted by the laser, and
- d) a threshold current of said laser.
Dependencies are inferred from the claim text.